1. Field of the Invention
The invention relates to slide fasteners and particularly to methods and apparatus for the manufacture of molded interlocking elements for slide fasteners.
2. Description of the Prior Art
The prior art, as exemplified in U.S. Patent No. 2,496,926, No. 3,179,996, No. 3,328,857, No. 3,414,948, No. 3,445,915, No. 3,487,531, and No. 3,770,862 and British Patents No. 446,336 and No. 871,458, contains a number of slide fasteners with fastening elements or scoops made by molding metal or thermoplastic resins. In one prior art technique of forming fastener elements by molding thermoplastics in a cavity wheel, the molten thermoplastic is injected directly into cavities defining the fastener elements from an injection shoe engaging the wheel; such molded fastener elements are often subject to failure and breakage at the leg portions adjacent the head portion during use or when folded to form the elements from elongated straight molded bodies. Additionally, it has been previously suggested to utilize a band to enclose the cavities in the cavity wheel with holes through the band for passing the molten thermoplastic from an injection shoe slidingly engaging the band; such manufacture of molded fastening elements requiring a band with accurately formed holes as well as requiring the stripping of flash and the like formed between the injection shoe and the band to allow separation of the train of fastening elements from the band.